It is often necessary for an entity to verify the location of a particular device. The entity may possess the device, or an employee or customer of the entity may have it, etc. Indeed, in some cases, the owner/user of the device may himself wish to prove where he (or at least the device in his control) was at a given time.
To establish the device's location, the entity may even today receive a plaintext or graphical indication of the geolocation from the device. For example, many smart phones have a built-in geolocation engine, such as a Global Positioning System (GPS) sub-system, which interfaces with an internal or network-accessible mapping routine. However, the transmitted indication may be spoofed, for example, by substituting an indication of another geolocation.
In some cases, system administrators—either human or automated—can locate a device using existing technology. For example, even now, administrators of mobile telephones can locate a telephone (n particular, its SIM card) approximately by sensing the strength of its transmission at different cell towers. One disadvantage of such known multilateration/hyperbolic capabilities is that they do not provide a method to verify such geolocation information to an acceptable degree of reliability.
There is a need for a system that provides non-repudiable evidence of the entity's location that can be verified to a high degree of reliability.